The Galaxy S4 is now selling at a rate of four units per second. In comparison, the Galaxy S3 took 50 days to reach the 10 million sales mark.

JK Shin, CEO and President of the IT & Mobile Communications Division at Samsung Electronics, said: "On behalf of Samsung, I would like to thank the millions of customers around the world who have chosen the Samsung Galaxy S4.

"At Samsung we'll continue to pursue innovation inspired by and for people."

The smartphone is currently available in over 110 countries and will gradually be rolled out to a total of 155 countries, in co-operation with 327 partners.

Samsung will add new colors this summer, including Blue Arctic and Red Aurora, followed by Purple Mirage and Brown Autumn.